I note from your subsequent post that you have more than one - but that they
are on half-charge.

What I mean by that, is that the input is 1 - 5 (5 being full chat)
and the dial is set to 2.5. I have no real understanding of how this
relates to chucking heat out during the day. I assumed that at this
setting, the heater charges half way, or only consumes half the
electricity, kind of, er...

Andy.